Core taking apparatus



July 13, 1943. J, E. HOFFOSS CORE TAKING APPARATUS Filed July 5, 1942 v w M o 4. E A an iv I I l l J Patented July 13, 1943 CORE TAKING APPARATUS John E. Hofioss, Houston, Tex, assignor to Reed Roller Bit Company, Houston, Tex., a-corporation of Texas Application July 3, 1942, Serial No. 449,566

8 Claims.

This invention relates in general to core taking apparatus and has for its general object the provision of a means for causing a wireline core barrel to be rotated with its core drill.

Various means have in the past been devised for causing the core barrel of awireline coring apparatus to rotate with the drill bit during the taking of a core. Some of these have however been complicated and easy to get out of order and others have been of such a nature that in one way or the other they interfered with the proper functioning of the apparatus.

It is therefore an object of this invention to provide an improved apparatus for causing a wireline core barrel to rotate with the drill bit during the taking of a core.

Another object of this invention is to provide such a device which will be extremely simple and easy to construct.

Another object of this invention is to provide such a device which will not substantially interfere with the flow of slush through the drill bit.

Another object of this invention is to provide a device for the purpose set forth which will firmly and positively engage both the core barrel and the drill stem or drill bit so as to positively transmit the rotative movement of the drill stem to the core barrel.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawing wherein is set forth by way of illustration one embodiment of this invention,

In the drawing:

Fig. 1 is a view partly in side elevation and partly in longitudinal cross section illustrating the upper portion of a core barrel of the wireline core barrel type.

Fig. 2 is a fragmentary view taken in longitudinal cross section along the line 2-2 of Fig. 1.

Fig. 3 is a transverse cross section taken along the line 3-3 of Fig. 1.

Fig. 4 is a longitudinal cross section through a core barrel and the lower end of a drill stem and core bit all constructed in accordance with this invention.

Fig. 5 is a transverse cross section taken along the line 5-5 of Fig. 4, and illustrating more in detail the driving mechanism constructed in accordance with this invention.

Referring now more in detail to the drawing, the numeral I illustrates the upper core barrel which may be of any usual form and which carries on its upper end a fitting 2 to which is secured the back pressure valve cage 3. Within this valve cage is the ball valve 4 adapted to seat against a suitable valve seat 5 held in place by means of a nut 6. This cage is provided with passageways so that fluid may escape from within the core barrel during the taking of ac'ore but the ball valve 4 will prevent the flow of fluid from above the core barrel into the same.

Integral with the cage 3 and extending upwardly therefrom is a portion which is slotted through to receive the holddown shoes or dogs I and 8 respectively. This portion is also provided with a bore adapted to receive the plunger 9 which is normally urged inan upward direction by means of the spring l0. Adjacent the upper end of this plunger it is provided with an en largement [I which receives the upper end of the spring it), and above this enlargement is a spearhead l2 adapted to receive an overshot in the well known manner for the purpose of withdrawing the core barrel.

Each of the'shoes l and 8 is provided with a slotl3 adjacent its lower end, the same being inclined downwardly and inwardly away from the friction face of the particular shoe. A similar slot 14 is provided adjacent the upper end of each of these shoes. A pin l5 extends through the slots in the lower ends of the shoes and is anchored at its opposite ends in the opposite side portions of the body 3. A second pin l6 extends through the upper slots l4 and is anchored at its opposite ends within the bifurcated lower end of the plunger 9 which straddles the upper end portions of the shoes I and 8.

It will be readily seen that when the plunger is in its uppermost position as illustrated both of the shoes I and 8 will be drawn inwardly to hold them out of contact with the interior of the drill stem. When, however, slush is pumped downwardly through the drill stem the same will impinge upon the enlargement II and will thus urge the plunger downwardly to cause the shoes "i and 8 to expand into frictional engagement with the interior of the drill stem and serve to hold the core barrel down.

On the lower end of the upper core barrel I there is connected by means of a nipple iii a lower core barrel I9. This lower core barrel It is provided with splined portions formed between the'gr'ooves 2|] that are spaced circumferentially about the outer surface of this lower core barrel. These grooves 20 as will appear inFig. 5 ar'e'deep' adjacent one edge thereof and taper outwardly to the surface of the core barrel adjacent the other edge.

On the lower end of this lower core barrel is provided a protruding cutter head 2| adapted to receive the core catcher 22 therein. This cutter head 2| is adapted to protrude below the lower portion of the bit head 24. The bit head is of any usual construction and in this instance is shown as having drag teeth 25.

The drill bit is mounted in the usual manner on the lower end of a drill collar or the like 26, the same being connected thereto in this instance by means of a fitting 21.

The drill bit, however, is of slightly extra ordinary construction in its shank which is made unusually long in order that it might receive the driving sleeve 28. This sleeve is made of a substantially cylindrical member and has portions adjacent its opposite sides pressed both radially inwardly and radially outwardly, the portions pressed radially inwardly being indicated at 29 in Fig. 5 and those pressed radially outwardly being indicated at 30 in Fig. 5. Those portions which are pressed radially inwardly are adapted to engage within the grooves 20 in the lower core barrel hereinbefore described. Those portions 30 which are pressed radially outwardly are adapted to engage within milled out slots 3| in the interior of the shank of the bit.

The lower end of the driving sleeve may be seated upon the slush ring 32 which is customarily provided within these drill bits, and the sleeve is held within the drill bit by means of a split ring 33 slipped into an appropriate slot above the driving sleeve.

It will be seen that this driving mechanism just described will be extremely efiicient in driving a core barrel with the drill bit during the taking of a core, that it is very simple in construction and very easy and cheap to manufacture, and is positive in its operation, yet that it will not interfere substantially with the normal now of drilling fluid through the drill bit.

It will be understood that while this invention has been described in connection with a core barrel having a protruding cutter head on its lower end, it may be used as well in connection with a barrel adapted to seat in a core bit, the bit itself carrying the teeth which cut the core.

An apparatus has therefore been provided which is fully capable of carrying out all of the objects and advantages sought by this invention.

Having described my invention, I claim:

1. In a coring apparatus, a core drill, a core barrel within said core drill and having a circumferentially facing abutment on its exterior surface, and a driving finger carried by said core drill and extending inwardly in a direction substantially tangential with respect to said core barrel to engage the abutment on said core barrel and cause the same to rotate with said core drill.

2. In a coring apparatus, a core drill, a core barrel within said core drill, means within said core drill and in engagement with a portion of said core barrel to prevent rotation of said means with respect to said core barrel, said core drill having a lateral recess in its inner wall, and a finger on said means extending into said lateral recess to prevent said core drill from rotating with respect to said means, whereby when said core drill is rotated said means and said core barrel will be caused to rotate with the core drill and relative rotation of the core drill with respect to the core barrel will be prevented.

3. In a coring apparatus, a core drill, a core barrel within said core drill, a sleeve in said core drill and fixed against rotation with respect thereto, and a finger on said sleeve extending inwardly in a direction generally tangential with respect to said core barrel, said core barrel having a recess in its outer face adapted to receive said finger, whereby said core barrel will be prevented from rotation with respect to said core drill.

4. In a coring apparatus, a core drill, a core barrel within said core drill, said core barrel and core drill having recesses formed in their adjacent surfaces, a driving connecting means in the space between said core barrel and core drill, said means including a sleeve surrounding the core barrel within the core drill, and said sleeve having parts struck out therefrom in in- Ward and outward directions and adapted to engage the recesses in said core drill and core barrel respectively, whereby rotation of said core drill will cause rotation of said core barrel.

5. As a subcombination, a driving element for causing rotation of a core drill to drive a core barrel located therein, said element comprising a sleeve having parts struck inwardly and outwardly therefrom, the part struck inwardly having its free edge extending in one direction circumferentially with respect to the sleeve and the part struck outwardly having its free edge extending in the opposite direction circumferentially with respect to the sleeve.

6. As a subcombination, a driving element for causing rotation of a core drill to drive a core barrel located therein, said element comprising a sleeve having parts struck inwardly and outwardly therefrom, the part struck inwardly having its free edge extending in one direction circumferentially with respect to the sleeve and the part struck outwardly having its free edge extending in the opposite direction circumferentially with respect to the sleeve, the opposite end portions of said sleeve forming continuous annular parts.

7. As a subcombination, an element adapted to form a portion of a core barrel to be positioned within a core drill during the taking of a core, said element comprising a sleeve-like part having a groove in its outer surface extending longitudinally thereof, said groove being generally V- shaped and having one side extending substan tially radially to provide a circumferentially facing abutment and the other side sloping gradually outwardly to the outer surface of the element, whereby a driving projection may abut said shoulder to rotate said element in one direction but will ride up on said sloping surface and not cause rotation of said element in the other direction.

8. A core drill adapted to receive a core barrel, said core drill having an opening therethrough, a zone within said opening adapted to receive a driving means for engaging a core barrel and causing the core barrel to rotate with the core drill, and the inner surface of said core drill within said zone having a lateral recess formed therein adapted to receive a finger, one wall of said recess providing a relatively sharp shoulder to receive a driving projection, and the other wall of said recess sloping gradually inwardly to the inner surface of the core drill.

JOHN E. HOFFOSS. 

